Undervolting (and underclocking) - Disadvantages ??

[kstuart]

Hello,

What are the disadvantages of Undervolting the CPU and/or Underclocking the GPU ?

If you think there are none, why wouldn't IBM/Lenovo implement the same utilities as a standard part of the product, and thereby be able to boast longer battery life and lower temperatures ?

[christopher_wolf]

With undervolting, you can go below a certian voltage for a given clock; this can lead to the system becoming highly unstable. With underclocking, there is a harder limit. Namely the lowest clock multiplier you can set. On the T43, you can go as low as 800Mhz, on the T4{2, 1, 0} you can go to 600Mhz. You get as slower response from the CPU. In addition, undervolting is a touchy proposition if you do not stress test your system afterwards. For example, under a light load, you may not notice any problems; after, however, you have started the CPU intensive program your system will become unstable very quickly. Intel also gives you free range to clock down its chispets via SpeedStep and whatnot, undervolting and going as low as you can go basicallygive you a little more of an edge; yet it isn't something that IBM/Lenovo is going to rush to implement on top of the power managers that they already ship with the ThinkPads.

[borez]

With undervolting, you can go below a certian voltage for a given clock; this can lead to the system becoming highly unstable. With underclocking, there is a harder limit. Namely the lowest clock multiplier you can set. On the T43, you can go as low as 800Mhz, on the T4{2, 1, 0} you can go to 600Mhz. You get as slower response from the CPU. In addition, undervolting is a touchy proposition if you do not stress test your system afterwards. For example, under a light load, you may not notice any problems; after, however, you have started the CPU intensive program your system will become unstable very quickly. Intel also gives you free range to clock down its chispets via SpeedStep and whatnot, undervolting and going as low as you can go basicallygive you a little more of an edge; yet it isn't something that IBM/Lenovo is going to rush to implement on top of the power managers that they already ship with the ThinkPads.

Just to add on:

It would definitely be difficult for Lenovo to implement undervolting for each Thinkpad out of the box, as different CPUs (different clockspeeds, different batches) have different undervolting thresholds.

Don't think they'll go to the limit of individually stress-testing each CPU one by one.

[kstuart]

Isn't there an undervolting threshold that one could consider safe without having to do stress testing (i.e. a lesser amount of undervolting) ?